It’s dumping snow…somewhere in the world. In Hakuba it’s raining in the valley, harder than it was this morning; and with our weather station registering -0.1 degrees at 2080 m asl I get the feeling it’s not gonna be falling as the best of snow even up top today. It’s easy to be glum but those climbing to high enough altitudes have been getting some decent powder apparently.
Pretty sad when the only good news is that its not gonna be raining tomorrow. Lets worry about the weekend when we get closer to it eh.
SNOW STABILITY INFORMATION:
The weather of late has been very unstable with rapid warming and equally as rapid cooling‚ 3 rain events under 1600 metres in the last 5 days along with cooling and rains turning to snow in the valley. Yesterday afternoon’s rain has setup into a hard crust at the surface below tree line with overnight clearing and cooling. New snow at elevation fell with mild temperatures yesterday and will be easy to warm on solar aspects and especially around rocks‚ trees and under cornices. Forecasted rain below tree line today‚ February 25th‚ will once again add free water and weight to the snow pack thus decreasing stability. New snow above freezing level will also be adding weight to the snowpack. Any new snow over the ice crust created overnight will see high probability of point release slides on steep convex slopes in avalanche terrain. Recent snow in the alpine is over riding the February 20th rain crust and point releases and size 1 slab avalanches were observed on South East aspects around rocks and in wind loaded gullies.
February 23rd North aspect‚ 13:10 @ 2000m Happo One:
CTM (11‚13) Resistant Planer‚ down 25cm in the new snow on facets and decomposing crystals 2cms above the Rain Crust of Feb. 20th
February 24th East aspect‚ 14:20 @ 2000m Tsugaike‚ Yamakami no One:
CTE(5) Sudden Collapse‚ down 65cm on crust
CTE(7) Resistant planer‚ down 75cm at Facet / melt freeze crust interface
CTH(22) Sudden planer‚ down 75cm at Facet / melt freeze crust interface
Skier controlled size 1 on East aspect‚ 38 degree slope @ 2000m Tsugaike‚ Yamakami no One.
Travel in unsupported steep terrain with the multiple layers of new snow on top of the Feb. 15th and Feb. 20th rain crusts should be avoided until bonding of the new and old snow layers takes place. Overnight clearing is supporting the creation of facets at the ice crusts / new snow interface. Areas below trees are still retaining the warmth from the rain and warm weather‚ solar radiation and rain could rapidly loosen the present moist snow pack. With this in mind it is still possible that weak layers within the wet snow may produce a wet slide with warm temperatures or solar radiation. Slides within the new snow once snow amounts increase is also a concern. New snow on the Feb. 20th sun crust may also prove to be a concern with increased snow fall or day time warming.
Avoid steep rocky or sparsely treed slopes on solar radiated aspects.
Avalanche Hazard Rating:
Below Tree Line: Considerable trending to High danger with rapid warming and rain.
Tree Line: Considerable trending to High Danger with increased rain or snow.
Alpine: Considerable trending to High Danger with increased snow and wind.
*Increased snowfall adding load to buried week layer
*Increase in loose snow avalanches and suffs
*Warming of surface snow causing instability in surface and near surface layers
*Use caution if crossing solar radiated slopes.
*Increased instability of solar aspect start zones especially under cornices and very steep slopes.
*Increased caution advised around rocky outcroppings‚ cliffs and well spaced trees in start zones.
*Development of cornices in lee slopes
*Lee side loading
*Windward scouring of ridges and rock out-crops creating uneven loading of slopes
*Due caution on cross loaded slopes
*Poor bonding at or around buried crust
*Facet layer around buried crust
*Wide propagation due to wind slab
*Stay away from steep and convex terrain
Danger level 3 : Considerable
Natural avalanches possible. Human triggered avalanches probable.
Danger level ratings are set for conditions at tree line
and may vary from below tree line and High Alpine areas.
Use this information as a guideline only.